Video report by ITV News Correspondent Neil Connery
A British explorer has become the first to sail anti-clockwise around the north pole in a single summer season - because of the retreat of arctic ice.
David Hempleman Adams sailed his boat through the north east passage above Russia and into the north west passage above Canada - something never possible before, even in summer.
The founder of Wicked Weather Watch - a UK based charity raising awareness of climate change among young people - has been coming to the area for 30 years.
But thanks to climate change, this year the ice is at its second lowest ever extent.
Filming his expedition exclusively for ITV News, David said: "The first British team to do the north east and north west passage anti-clockwise in one season, which is slightly worrying because the whole thing was to make people aware of the climate and what's happening up in the high arctic.
"But I never realised how extreme the conditions have been in the sense of no ice whatsoever."
Among the crew of six on board was 14-year-old Benji Edwards, who is determined to spread the message about the effects of climate change to a younger audience.
"It is really nice to have achieved what we set out to," he said. "There has however been alarmingly little ice in the north west passage."
Scientists measuring the retreat of ice are also alarmed by the dramatic speed of shrinkage and thinning.
Professor Julienne Stroeve, from the US National Snow and Ice Data Centre, said: "The pace of decline right now in the arctic sea ice is happening much faster than a lot of the models have forcasted would happen.
"It's not totally unexpected given what we know now about how thin the ice has become, so you're more likely to have less ice."
Scientists predict that the arctic region could have its first ice-free summer by 2040.